Knitting machine



March 11 1952 A. BELFORD 2,588,473

KNITTING MACHINE Filed Nov. 16. 1949 3 Sheets-Sheet 1 10 H W H 14 x 1-lHlk- 1B INVENTOR. l ALEXANDER BELFORD BY I @(VY Y @7 ATTORNEY March11, 1952 Filed Nov.

A- BELFORD KNITTING MACHINE 3 Sheets-Sheet 2 INVENTOR. ALEXANDER BELFORDaw Y Q I ATTORNE S.

March 11, 1952 BELFORD 2,588,473

KNITTING MACHINE Filed New. 16, 1949 5 Sheets-Sheet 3 INVENTOR.ALEXANDER BELFORD ATTORNEY Patented Mar. 11, 1952 UN I'TED STAT ES O F2,588,473

KNITTING MACHINE Alexander Belford', Laconia, N Hg, a's's'igiibr toScott & Williams, Incorporated; Eac'onia; N: H., acorporation ofMassachusetts Application November 16, 1949, Serial-No. 127,689

Claims.

This invention relates to knitting. machines and in particular hasreference to the control of wrap yarns to. secure proper plating of amain yarn or yarns.

Considerable difliculty has been encountered when attempting to plateone or more main yarns with wrap yarns fed to groups. of selectedneedles dueto the factthat satisfactory control of the relationship ofthe wrap and main yarns could not be maintained. So-called plating cams.have been provided toimprove the plating. by exerting a degree ofcontrol but these plating cams. have not exerted sufficient control toinsure proper plating under conditions ofvariations in the selection ofgroups of needles being wrapped.

The broad object of the present invention may be stated to be theprovision of control means to secure proper plating by wrap yarns. Inaccordance with the invention there is provided a special type ofplating cam bearing, in particular, proper relationship to a stitch camand sinkers and having a controlling edge properly contouredv toefiect-desired control. Additionally, in accordance with the inventionspecial sinkers are provided which cooperate with the plating cam and;in particular, permit it to depressthe wrap yarn to proper extents andpositions forsecuring. most effective plating.

Further, in accordancewith the invention,.it. is possible to-wrap witha-heavy wrap yarn more needles thanhas been heretofore possible, thisend being achieved by quick reliefoi' strain. on leadingstitches of awrapped panel after their formation.

Subsidiary objects of the invention relate to these and other details ofconstruction. and'operation and will become apparent from the'folflowingdescription read in conjunctionwiththe accompanying drawings in which:

Figure 1 is a fragmentary view partlyin sec tion looking radiallyoutwardly of the. needle cylinder at those parts of the machine whichare particularly concerned with the operation of plating bya wrap yarn;

Figure 2 is a fragmentary" radialsection showing the relationshipsexisting in Figure 1 be tween the last needle to take a wrap yarnin' acourse, an associated sinker and the associated plating cam;

Figure 3 is a view similar to Figure 1 but showing a later event, thewrap yarnhavingbeen drawn onto the platform of a sinker adjacent to thelast needle wrapped'in the course; and

Figure 4 is a view similar toFigureZshowihg the'relationships existingin Figure 3;

2. Inasmuch as the invention is applicable to cular knittingmachinesiiigeneral and concerns only particular pa'r't's-of'sucli machine),thereare illustrated and described only those parts" which" are directlyconcerned with the present invention. As an example'of the type" ofmachirie'te which the' invention applicable" there ma'yfbe' referred" tothe patent to I. W; .Grothe'y" No; 2,138,738; dated November 29,1938,which; inpar' ticular, in Figures 2"and"3"illustrates the mount?- ingand arrangement of a plating dam of l the" general'type referred toabove.

Lat'chneedles" 2' independently mountediiisldts" in" aconventional'needle'cylinder (not"illustr"ated)' are provided with butts4 which areac'ted upon" by cams including a stitch ca'r'riahavin'g'anedge" 6 for engagingfthebutts' andm'oving the needles"downwardly in" the stitch drawing operation. This stitehcam isgenerallycoriventional but'its" edge 6 may be somewhat steeper than"usual, for? l which is'als'o' steep ('e. g. 48") whicl'i'is lficate'dabove an edge 9 of a relief cam,.whicl1"edge' also steep; for example;havingant'aiigle'of about" 47with'the horizontal. As'will appear "fromthe discussion hereafter a steep angleon the" stitch cam? while"desirable has heretofore hadan objection" use when wrapping. wasinvolved: In acc'o'rdance' with the present invention" a" steep stitch;cam may be used with no objectionable" Further more detailed" referenceto? the" results. relief cam will b'emadeiater;

On'eor m'orem'ain yarns are fed fromcorrespo'nding'feeding fingers" andin the presentcase' one such" feeding finger is indicated at 10; thisneedles from thethro'at l2 o'fthelatch ring I 4."

The platingcam' IB located during plating" operations in the positionillustrated i'n' the figures and-may be-mounted in the same fashionas'the' plating carr'lillustrated in theGro'they pat ent referredto above:Accordingly; the mounifhas. thesame' slope'as' the e'dgeii ofthe' stitchcam. At it's 'lower" endtheportion-H merges the" cam which" iscontinued? as a" further are. at 282" As will hereafter appear thesevarious poi-- tions of" the cam edge have" individual" andii'n'rDOrtant' functions:

The various wrap yarns are fed from individual wrap fingers and one yarnW and its corresponding wrap finger 3D is illustrated. The wrapping maybe carried out in any of the conventional fashions used for panelwrapping. For example, the method of wrapping may be that of the Grotheypatent. In brief, in any such wrapping operation a wrap finger isnormally located inside the needle circle and when wrapping is to occurit is projected outside the needle circle and then by one of variousalternative means the wrap yarn is caused to be delayed relative to themoving needles so that the wrap yarn is laid below the hooks and abovethe latches of those needles which are to be wrapped. Selection tosecure various patterns is generally accomplished by the selectiveprojection of the needles in position to take the wrap yarn, thoseneedles which are not to take the yarn remaining low so as to miss it.Alternatively, the

needles which are not to take the wrap yarn may beprojected to anunusually elevated position so that the wrap yarn will be placed on thembelow their latches and will not be entrapped in the hooks during yarndrawing operations. If the former procedure is adopted and intermediateneedles of a group are not to be wrapped while end needles of a groupare to be wrapped, the needles of the group which are not to be wrappedwill eventually ride along with the Wrapped needles and in attainingsuch position they will rise outside the wrap yarn extending betweenneedles which are wrapped. This is designated as interlacing and suchinterlacing is illustrated in Figure 1 in which the needles 2A and 2Dare wrapped while the intermediate needles 2B and 2C are not wrapped,these needles in Figure 1 being located with their upper ends outsidethe wrap yarn extending between the needles 2A and 2D. As illustratedthe needle 2A is the last of the needles to be wrapped in the coursewhich is being formed. 2D may be either the first needle of a groupwhich is wrapped or may be one of several of the first needles of thegroup which are wrapped. It may be here noted that the wrap yarn willextend from the last needle to be wrapped in the preceding or someearlier course in the fabric F to the first needle of the group underconsideration. The portion of the wrap. yarn thus extending from apreceding course must also be properly controlled as will be describedin more detail hereafter.

Sinkers. 32 are mounted between the needles and have a wave impartedthereto in.the usual fashion. The ledges of the sinkers over whichtheyarns are drawn are indicated at 34. In some cases it is desirablethat the sinkers when moved inwardly should aid in moving the fabric Finwardly and for this purpose some of the sinkers are provided withrounded teeth indicated at 36. A usual set-up of sinkers involves thealternation of such toothed sinkers with plain sinkers,' the inner endsof which have smooth and rounded upper edges as continuations of theledges 34. When the action of sinkers on the fabric is not required allof the sinkers may be of the smooth variety. In accordance with thepresent invention there is located inwardly of the ledge 34 a depressionin the form of a notch 38 which is aligned directly below the platingcam I6 when the sinkers are in the positions which they attain at thetime stitches are drawn. At this time the notches or depressions 38 arelocated immediately inwardly of the backs of the needles as indicated in4 Figures 2 and 4, the sinker ledge 34 terminating inwardlyapproximately at the radius of the backs of the needles.

The parts entering into the control of the yarns having now beendescribed, there may be discussed the functions and operations of theseparts.

It has been recognized that a wrap yarn could be more positively platedover a main yarn or yarns if the needles could be passed down the stitchcam more rapidly than usual and to do this and still maintain a properpath the usual practice would have been to make the operating edge ofthe stitch cam somewhat concave so that the downward rate of movement ofthe needles would be accelerated as they passed down the stitchcam.However, due to the fact that the underside of the plating cam wasshaped as an are, as illustrated in said Grothey patent, which wouldamount to its having a shape, referring to the present drawingsinvolving a continuation of the edge I8 convexly down to its lowermostportion 25, the wrap yarn would have been held so low on the cheek ofthe last needle to be wrapped that as the latch of this needle wasclosed by the stitch held on the needle the wrap yarn would have beentrapped and broken fibers, spoiling the appearance of the fabric, wouldhave resulted. The slope of the stitch cam accordingly was limited byconsideration of the fact that the wrap yarn had to be held sufiicientlyhigh to prevent entrapment.

In accordance with the present invention the initially active portion l8of the edge of the plating cam, which portion of the edge acts in theusual fashion to control the position of the wrap yarn during initialmovement of the needles by the stitch cam, is followed by asubstantially horizontal portion 20 and then by a further slopingportion 22. The result is that the lowering of the wrap yarn by theplating cam is momentarily interrupted so that when it is again moveddownwardly by th plating cam it will be located relatively high in theneedle hooks. To achieve proper results the operating angle of thestitch cam is stee ened, for example to about 47, in effeet by advancingthe bottom of the stitch forming edge to the right but without changingthe relationship of the contact point of the needle butt with the stitchcam edge with respect to the main yarn feed. The edge portion 22 of theplating cam is at the same angle as the active edge of the stitch camwith the result that the wrap yarn is caused to move at the point whereit engages the last needle which is wrapped in a path nearly parallelwith the path of the main yarn and with the path of the upper ends ofthe needles. Accordingly, the relationships of the wrap and main yarnsto each other and to the needle hook are maintained substantiallyconstant from the time the wrap yarn engages the portion 22 of theplating cam until the yarns engage the sinker ledges. This maintenanceof relative positions insures a proper plating relar tionship at thetime the needle hook starts to draw the main and wrap yarns through thepreviously formed loop.

For proper plating the wrap yarn must be held in the back of theneedlehook when it is drawn over the sinker platform or ledge 34. Thebottom 26 of the plating cam should be low enough so that the wrap yarnwould extend horizontally from beneath the plating cam to its positionin the hook. In past arrangements the plating cam could not be set lowenough to insure such a direction of feed due. to the fact that thewrapyam aswell as the previously formed fabricwassupported by thehorizontal. conventional .sinker ledge to a point extending inwardlyunder and beyond the plating cam. To insure the possibility of asufliciently low position. of the plating cam, the depressions ornotches 38 are provided in the toothed sinkers while a correspondingclearance is'provided in the conventional sinkers Without teeth byshortening the ledges or platforms so that when in the positionillustrated the ledges or platforms will not extend inwardly of thebacks of the needles. The depressions or clearances thus provided in allof the sinkers allow the plating cam to be set. sufficiently low forpositive plating but provide a space into which the previously formedfabric and the wrap yarn may be depressed. This avoids the production ofrubbing friction which would tend to produce fuzzing of the yarns. tion28 of the plating cam beyond its lowermost portion 26 as an arc ofsubstantial radius is also important. Considering the first needle of agroup to be wrapped the wrap yarn will extend to this needle from thewrapped stitch of the fabric in which it was previously knitted, aroundthis needle and thence possibly on the outside of additional needleswhich are to be wrapped and on the inside of interlacing needles whichare not to be wrapped. Tension is applied to the wrap yarn by means of aconventional spring take-up which is not shown herein and, since theyarn extends upwardly from the first needle to be wrapped as that needleapproaches the yarn drawing point, it will be evident that the appliedtension may cause the wrap yarn to be located so far up in the needlehook as to be clamped on top of the main yarn and thus produce animproperly plated stitch. The portion of the wrap yarn extending fromthe last needle wrapped to the wrap finger will be cammed downwardly bythe plating cam but must not be suddenly released for possible upwardmovement immediately after it passes the lowest point of the platingcam. The large radius at 28 will serve to hold this portion of the yarndownwardly even beyond the lowermost point of the plating cam to insurethat it will maintain its proper relationship to the main yarn or yarnsuntil the stitch is sufficiently drawn so that it cannot thereafter getout of its proper relative position.

It may be noted that the lowermost point of the plating cam is, asillustrated in Figures 1 and 3, at that point where the drawing of theyarns for new loops commences.

As a result of the foregoing the plating cam assumes and maintainscontrol of the wrap yarn to insure continuously, so long as apossibility of change of relative positions could occur, the properrelationship of the wrap yarn to the main yarn or yarns and to the hooksof the needles.

In order to give wrapped stitches more prominence it is often desirableto use a wrap yarn heavier than that from which the main fabric is knit,and when several consecutive needles are wrapped with such a wrap yarnthe result is an exceptionally heavy fabric over a local area. In thepast, it has not generally been practical to wrap more than threeconsecutive needles with a single heavy yarn and even this has beenpossible only due to the fact that "robbing of yarn occurs. In thepresent instance, as illustrated in Figure 1, the lower point of thestitch cam 8 is followed almost immediately by the The formation of theporrise 9. oft the relief cam, which rise occurs at a steep angle sothat the needles, after drawing their stitches, are raised suificientlyquickly to 1. In a: circular knitting machine, independent needles andsinkers, means for feeding a main yarn to the needles, means for feedinga wrapv yarn to a group of needles in a single course, cam means formoving needles-in a predetermined path for the seizure of the main yarn,andaplating cam locatedinside the needle circle and engageable with thewrap yarnat a part thereof be tween the last needle of a group to bewrapped and the wrap yarn supply. said sinkers having ledges over whichstitches are drawn and provided with clearances inwardly of the ledgesand adjacent to the plating cam when positioned at the circumferentialposition of closest approach of the plating cam to the sinkers, so thatthe wrap yarn may be located by the plating cam to extend therefromtowards a needle approximately parallel to the plane of the sinkerledges.

2. In a circular knitting machine, independent needles and sinkers,means for feeding a main yarn to the needles, means for feeding a wrapyarn to a group of needles in a single course, cam means for movingneedles in a predetermined path for the seizure of the main yarn, and aplating cam located inside the needle circle and engageable with thewrap yarn at a part thereof between the last needle of a group to bewrapped and the wrap yarn supply, said sinkers having ledges over whichstitches are drawn and provided with clearances inwardly of the ledgesand adjacent to the plating cam when positioned at the circumferentialposition of closest approach of the plating cam to the sinkers, so thatthe plating cam may press previously knitted fabric beyond the level ofthe sinker ledges.

3. In a circular knitting machine, independent needles and sinkers,means for feeding a main yarn to the needles, means for feeding a wrapyarn to a group of needles in a single course, cam means for movingneedles in a predetermined path for the seizure of the main yarn, and aplating cam located inside the needle circle and engageable with thewrap yarn at a part thereof between the last needle of a group to bewrapped and the wrap yarn supply, said sinkers having ledges over whichstitches are drawn and provided with clearances inwardly of the ledgesand adjacent to the plating cam when positioned at the circumferentialposition of closest approach of the plating cam to the sinkers, so thatthe wrap yarn may be located by the plating cam to extend therefromtowards a needle approximately parallel to the plane of the sinkerledges, at least some of said sinkers being provided with teeth formoving inwardly previously knitted fabric.

4. In a circular knitting machine, independent needles and sinkers,means for feeding a main yarn to the needles, means for feeding a wrapyarn to a group of needles in a single course, cam means for movingneedles in a predetermined path for the seizure of the main yarn, and aplating cam located inside the needle circle and engageable with thewrap yarn at a part thereof between the last needle of a group to bewrapped and the wrap yarn supply, said sinkers having ledges over whichstitches are drawn and provided with clearances inwardly of the ledgesand adjacent to the plating cam when positioned at the circumferentialposition of closest approach of the plating cam to the sinkers, so thatthe plating cam may press previously knitted fabric beyond the level ofthe sinker ledges, at least some of said sinkers being provided withteeth for. moving inwardly previously knitted fabric.

5. In a circular knitting machine, independent needles and sinkers,means for feeding a main yarn to the needles, means for feeding a wrapyarn to a group of needles in a single course, a steep stitch cam formoving needles in a predetermined path for the seizure of the main yarn,a plating cam located inside the needle circle and engageable with thewrap yarn at a part thereof between the last needle of a group to bewrapped and the wrap yarn supply, said plating, cam having an extendedportion thereof engageable with the wrap yarn approximately parallel tosaid predetermined path of the needles, said stitch cam having a fiatbottom portion for maintaining the level of the needles for a shortportion of their path of movement. and cam means for steeply reversingthe movements of needles immediately following their release by saidfiat bottom portion of the stitch cam, thereby to relieve tension ondrawn stitches.

ALEXANDER BELFORD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,200,140 Robinson Oct. 3, 19161,214,828 Robinson Feb. 6, 1917 2,138,738 Grothey Nov. 29, 19382,263,492 Grothey Nov. 18, 1941 2,555,870 Bristow June 5, 1951

